1. Field of the Invention
This invention relates to Totally Enclosed Fan Cooled (TEFC) electric motors, particularly to a form-fitting device for substantially covering TEFC motors to thereby reduce exposure to chemicals, spray, moisture, splash, air-borne and other forms of debris and enhance motor efficiency through improved cooling system airflow.
2. Description of Prior Art
Typically, TEFC motors employed in the pulp and paper, textile, petrochemical, mining, lumber and other process industries are subjected to conditions detrimental to the motor life and operation. Such motors are placed in environments where moisture, splash, spray, and air borne debris regularly block the motor cooling system consisting of air intake fan protected by an outer grill, and cooling fins along the length of the motor housing. Such blockage has been proven to dramatically reduce motor life and diminish motor performance and efficiency. Such blockage has been proven to cause higher maintenance costs, higher energy usage, reduced load capacity, shortens bearing and winding life, and causes costly production disruptions and motor replacements all of which are very non-productive and costly to industry.
Daily conditions and immediate needs in most industrial situations place tremendous time constraints on maintenance personnel. Inventions that address such realities are more likely to be adopted and utilized as envisioned by the inventor. Previous attempt to address the problems associated with adverse industrial conditions typically involved haphazard, temporary solutions such as rubber mats thrown over motors to expensive, fabricated steel housings specially crafted to cover a motor. All of these prior devices attempt to serve a singular purpose of protecting a motor from various elements and all are also generally undesirable in practice, insufficient in function and may actually be harmful to the motor. The present invention involves a device that can be installed and removed without any tools or additional assistance.
Various inventors have attempted to address the problem of protecting motors from various elements but none have proposed a device, as proposed by the present invention, that protects a majority of the motor, addresses motor efficiency, and recognizes personnel maintenance time issues relative to the actual application of the invention.
The prior art has attempted to either address or circumvent some of the problem with various forms of enclosures yet most require tools and substantial time for application thereby limiting their application and do not adequately protect the entire motor cooling system. The prior art is limited to only protecting portions of motors from the problem but do not address or attempt to improve motor efficiency under both adverse and non-adverse conditions. The most comprehensive prior art to protect the motor cooling system is U.S. Pat. No. 5,311,090 (Expired).
The patentee of U.S. Pat. No. 5,311,090 (Expired) discloses a two (2) piece device consisting of a fan enclosure which can be attached to a shield encompassing a portion of the motor thereby protecting the upper surface areas of the motor from harmful elements. Such a device only partially addresses the problems associated with blockage of the motor cooling system by exposing the sides of the motor to harmful chemicals and debris, splash and spray originating from all points other than directly above the motor. Such device also requires the use of tools, and external means of attachment and does not account for actual situations in most industrial environments where maintenance personnel time is very limited thereby rendering its application to only the absolute worst of situations. In addition, to the aforementioned, the partial periphery of the cover device confines cooling airflow to only a portion of the motor shell subjecting the unexposed sides of the motor to potentially diminished airflow thereby allowing heat accumulation which leads to diminished efficiency and increased energy usage.
U.S. Pat. No. 4,220,880 describes an adjustable motor cover designed to protect outdoor motors from sun and rain. This reference although providing a motor covering and protection from various elements does not provide adequate ventilation or clearance in many motor installations and essentially places the motor in an oven-like structure thereby hastening the motor demise. This reference also appears to require that a motor be actually mounted to the cover itself. Such a requirement would render the cover useless in most indoors manufacturing applications whereby motors must be mounted to a specific base and coupled to an appurtenance such as a pump or pulley. Additionally the mounting requirement would preclude its use on many TEFC motors whose weight and load requirements would far exceed the support capacity of the referenced drawing. Further, this reference may actually reduce, in some situations, motor efficiency. The present invention provides protection from sun, rain, ambient temperature, is applicable indoors or outdoors, and reduces losses in motor efficiency caused by heat.
U.S. Pat. No. 5,006,742 discloses a splash-proof cover for an electric motor with an electrical socket connection. Such cover only provides a splash type cover and does not address fan intake areas, or substantially protect the motor cooling surface areas along the motor housing. In addition, said cover does not attempt to address motor efficiency gains through improved cooling.
Additional prior art generally within the field of the present invention includes U.S. Pat. Nos. 4,631,433, 3,719,843, 4945,270 and 4,931,681.